Data carrier with a module with a reinforcement strip

ABSTRACT

In a lead-frame configuration ( 60 ), a module ( 70 ) and a data carrier ( 72 ), two connecting plates ( 12, 13 ) of the module ( 70 ), which are each intended for connection to a connecting contact or bump ( 47,48 ) of a chip ( 41 ), are connected to a reinforcement film ( 66, 71 ) formed from a fiber-reinforced film of plastics material by means of a layer ( 73 ) of an adhesive that is particularly well suited to transmitting shear forces, in which case there is additionally provided in an advantageous further embodiment, on the reinforcement film ( 66, 71 ), at least one further layer ( 74, 75, 76 ) that is able to serve for protecting, damping or fastening purposes.

The invention relates to a lead-frame configuration that is strip-likein form, that has a frame base and that has a plurality of lead-framesthat are connected to the frame base and are situated next to oneanother in the longitudinal direction of the strip, each of whichlead-frames is intended to receive a chip, wherein each lead-frame hasat least two connecting plates, wherein there is provided for thelead-frames that are situated next to one another in the longitudinaldirection of the lead-frame strip a reinforcement strip that extends inthe longitudinal direction of the strip and is connected both to theframe base and to the connecting plates of each of the lead-frames thatare situated next to one another in the longitudinal direction of thelead-frame strip, the connection being made by means of a layer ofadhesive.

The invention further relates to a module that is produced with the helpof a lead-frame configuration and that has at least two connectingplates each of which is connected to a connecting contact or bump of achip, and that has a reinforcement ribbon that is connected to theconnecting plates, the connection being made with a layer of adhesive.

The invention further relates to a data carrier fitted with a module.

A lead-frame configuration of this kind, a module of this kind and adata carrier of this kind are known from U.S. Pat. No. 5,005,282 A. Inthese known designs, the reinforcement strip comprises a film ofplastics material that was marketed under the “KAPTON” trademark and thelayer of adhesive comprises an adhesive material that was marketed underthe “PYRALUX” trademark. The reinforcement strip is a simple fiber-freeplastics film and the adhesive is an ordinary adhesive, and althoughrelatively good mechanical reinforcement is obtained in this way bymeans of the reinforcement strip that is connected to the connectingplates via the layer of adhesive, it has been found that the knownsolution does not provide sufficiently great mechanical reinforcementwhen there are high mechanical loads on a module or on a data carrierhaving such a module, or in other words, that the known design meritsimprovement.

It is an object of the invention to provide a solution for the factorsmeriting improvement that have been specified above and to produce animproved lead-frame configuration, an improved module and an improveddata carrier.

To allow the above object to be achieved, there are provided in alead-frame configuration according to the invention features accordingto the invention, thus enabling a lead-frame configuration according tothe invention to be characterized as follows, namely:

A lead-frame configuration that is strip-like in form, that has a framebase and that has a plurality of lead-frames that are connected to theframe base and that are situated next to one another in the longitudinaldirection of the strip, each of which lead-frames is intended to receivea chip, wherein each lead-frame has at least two connecting plates,wherein there is provided for the lead-frames that are situated next toone another in the longitudinal direction of the strip a reinforcementstrip that extends in the longitudinal direction of the strip and isconnected both to the frame base and to the connecting plates of each ofthe lead-frames that are situated next to one another in thelongitudinal direction of the strip, the connection being made by meansof a layer of adhesive, wherein the reinforcement strip is formed by afiber-reinforced film of plastics material and wherein the layer ofadhesive is produced by means of an adhesive that is suitable fortransmitting shear forces that may possibly occur in the region betweenthe connecting plates on the one hand and the reinforcement strip on theother hand.

To allow the above object to be achieved, there are provided in a moduleaccording to the invention features according to the invention, thusenabling a module according to the invention to be characterized asfollows, namely:

A module that is produced with the help of a lead-frame configurationand that has at least two connecting plates each of which is connectedto a connecting contact or bump of a chip, and that has a reinforcementribbon that is connected to the connecting plates, the connection beingmade by means of a layer of adhesive, wherein the reinforcement ribbonis formed by a fiber-reinforced film of plastics material and whereinthe layer of adhesive is produced by means of an adhesive that issuitable for transmitting shear forces that may possibly occur in theregion between the connecting plates on the one hand and thereinforcement ribbon on the other hand.

To allow the above object to be achieved, there are provided in a datacarrier according to the invention features according to the invention,thus enabling a data carrier according to the invention to becharacterized as follows, namely that a data carrier according to theinvention contains a module according to the invention.

By the provision of the features according to the invention, there isobtained, in a manner which is structurally simple and also inexpensive,a mechanical reinforcing function that is appreciably improved over theknown solutions, the reason for this being that considerably highermechanical forces can be withstood by a fiber-reinforced film ofplastics material, it being ensured by means of the adhesive intended toconnect the fiber-reinforced film of plastics material to the connectingplates, which adhesive is particularly well suited to transmitting shearforces that may possibly occur in the region between the connectingplates on the one hand and the reinforcement strip on the other hand,that tensile or thrust forces that act on the connecting plates and thatoperate as shear forces as mentioned above are transmitted to thereinforcement strip or reinforcement ribbon of fiber-reinforced film ofplastics material without any adverse deformation of the layer ofadhesive, thus enabling the fiber-reinforced film of plastics material,which is able to take high mechanical loads, to withstand the whole ofsuch forces, thus ensuring that there cannot be any local displacementsof the connecting plates relative to the connecting contacts of thechip, which means that it is at all times ensured that the electricaland mechanical connections between the connecting plates and theconnecting contacts of the chip are protected against high mechanicalloads and that safe mechanical and electrical contact between theconnecting plates and the connecting contacts of the chip is ensured atall times. The advantages outlined above are particularly important whena lead-frame configuration according to the invention or a moduleaccording to the invention is intended for the manufacturer of a datacarrier and is used for this purpose and when a data carrier of thiskind is a label or tag that is intended for example for marking productsand is therefore connected to such products, because labels or tags ofthis kind may be subjected to high bending stresses, in which case highforces may then be exerted on the mechanical and electrical connectionsbetween the connecting plates and the connecting contacts of the chip.

In the case of the solutions according to the invention, it has provedadvantageous if at least one further layer is provided on thereinforcement strip or reinforcement ribbon formed by a fiber-reinforcedfilm of plastics material. It has proved particularly advantageous inthis case if there is provided on the reinforcement strip orreinforcement ribbon formed by a fiber-reinforced film of plasticsmaterial at least one further layer that belongs to the group of layersdetailed below, which group comprises: a protective layer that iscomposed of metal, a damping layer that is composed of a dampingmaterial and preferably of a paper-like material, and a fastening layerthat is composed of a fastening material and preferably of an adhesivematerial. What is additionally achieved in this way, in a simple andinexpensive manner, is that an additional protective function and, ifrequired, a damping function and a fastening function are obtained.

These and other aspects of the invention are apparent from and will beelucidated with reference to the embodiments described hereinafter.

IN THE DRAWINGS

FIG. 1 is a plan view from above showing part of a lead-frameconfiguration according to one embodiment of the invention, in whichlead-frame configuration no chips have, as yet, been connected to thelead-frames that it is shown to have.

FIG. 2 shows, in a similar way to FIG. 1, part of a lead-frameconfiguration according to one embodiment of the invention, in whichlead-frame configuration a chip has already been connected to thelead-frames that it is shown to have and the lead-frames are stillelectrically connected to the frame base.

FIG. 3 shows, in a similar way to FIGS. 1 and 2, a lead-frameconfiguration according to one embodiment of the invention, in whichlead-frame configuration a chip has already been connected to thelead-frames that it is shown to have and the lead-frames have beenelectrically isolated from the frame base.

FIG. 4 is an oblique view from above showing a module according to oneembodiment of the invention, which has been produced with the help of alead-frame configuration as shown in FIG. 3.

FIG. 5 is a section on line V-V showing, to a very much enlarged scale,a part of the module 70 shown in FIG. 4, in a state in which it is heldin a data carrier.

Part of a lead-frame configuration 1 is shown in FIG. 1. The lead-frameconfiguration 1 is strip-like in form and extends in a longitudinaldirection that is indicated in FIG. 1 by an arrow 2. The lead-frameconfiguration 1 has a frame base 3. Connected to the frame base 3 are aplurality of lead-frames that are situated next to one another in thelongitudinal direction 2 of the strip. The lead-frames are arranged intwo rows 4 and 5 in the present case. Of the total number of lead-framesprovided only six, 6, 7, 8, 9, 10 and 11, are shown in FIG. 1, in whichcase lead-frames 6, 7 and 8 make up the first row 4 and lead-frames 9,10 and 11 make up the second row 5. Each lead-frame 6 to 11 is intendedto receive a chip in this case. However, in the case of the lead-frameconfiguration 1 shown in FIG. 1, the chips have not yet been connectedto the lead-frame configuration 1 or rather to the lead-frames 6 to 11belonging to this lead-frame configuration 1.

The design of all the lead-frames 6 to 11 will be described in detailbelow, although this description will be given by reference only to thefirst lead-frame mentioned, 6.

Each lead-frame 6 to 11, and hence lead-frame 6 too, has two connectingplates 12 and 13. The connecting plates 12 and 13 are separated from theframe base 3 by a first narrow air-gap 14, a first aperture 15, a secondnarrow air-gap 16, a third narrow air-gap 17, a second aperture 18 and afourth narrow air-gap 19. Provided in the first connecting plate 12 areone complete elongated hole 20 and, adjacent thereto, a hole 21 and twohalf elongated holes 22 and 23, with the first half elongated hole 22opening into the first narrow air-gap 14 and the second half elongatedhole 23 opening into the second narrow air-gap 16. In the secondconnecting plate 13, there are likewise provided one complete elongatedhole 24 and, adjacent thereto, a hole 25 and two half elongated holes 26and 27, of which the first half elongated hole 26 opens into the fourthnarrow air-gap 19 and the second half elongated hole 27 opens into thethird narrow air-gap 17. What is achieved by the provision of the narrowair-gaps 14, 16, 17 and 19 and the apertures 15 and 18 is that there area total of three connecting bridges 28, 29 and 30 between the firstconnecting plate 12 and the frame base 3, by means of which both amechanical and an electrically conductive connection is made between thefirst connecting plate 12 and the frame base 3. In a similar way, thereare three further connecting bridges 31, 32 and 33 provided between thesecond connecting plate 13 and the frame base 3, by means of which botha mechanical and an electrically conductive connection is made betweenthe second connecting plate 13 and the frame base 3. Each of the twoconnecting plates 12 and 13 is intended to be connected to a chipconnection or bump of a chip.

The two connecting plates 12 and 13 of the lead-frame 6 define abridging zone 34 that can be bridged by means of a chip. In the case ofthe lead-frame configuration 1, the arrangement made is, with particularadvantage, such that the two connecting plates 12 and 13 of lead-frame6, and hence of all the other lead-frames 7, 8, 9, 10 and 11 too, aredirectly adjacent to one another, without any section of the lead-frame6 or, in the other cases, of the other lead-frames 7 to 11, intervening,and define a narrow air-gap 34 as a bridging zone 34. In the presentdesign, the air-gap 34 is arranged to extend obliquely to thelongitudinal direction 2 of the strip. This being the case, the air-gap34 is arranged to extend substantially in an S-shape, as can be seen inFIG. 1.

Shown in FIG. 2 is a lead-frame configuration 40 that is obtained byapplying further processing to the lead-frame configuration 1 shown inFIG. 1 and that differs from the lead-frame configuration 1 shown inFIG. 1 in that in the lead-frame configuration 40 shown in FIG. 2 thereis a chip 41, 42, 43, 44, 45, 46 connected to each lead-frame 6 to 11.The connection of each chip 41 to 46 to its lead-frame 6 to 11 isperformed in this case by a so-called “flip-chip technique”, which meansthat each chip 41 to 46 has been turned over or flipped and, in thatposition, has been set down on each pair of connecting plates 12 and 13in each lead-frame 6 to 11 by its chip connections or bumps, of whichthere are two in the present case, 47, 48 and 49, 50 and 51, 52 and 53,54 and 55, 56 and 57, 58, and has been connected thereto by anelectrically conductive connection. The connection between the chipconnections or bumps 47 to 58 and the connecting plates 12 and 13 ineach lead-frame 6 to 11 is made in the present case by a thermalcompression process. The connection between the chip connections orbumps 47 to 58 and the connecting plates 12 and 13 in each lead-frame 6to 11 may of course also be made in the present case by any otherprocess that is known per se.

Shown in FIG. 3 is a further lead-frame configuration 60 that isobtained by applying further processing to the lead-frame configuration40 shown in FIG. 2 and that differs from the lead-frame configuration 40shown in FIG. 2 in that the lead-frames 6 to 11 and the chips 41 to 46connected to the said lead-frames 6 to 11 have been electricallyisolated from the frame base 3. This is achieved by putting theconnecting bridges that were originally provided between the connectingplates 12 and 13 and the frame base 3 out of action, so doing by nowproviding in those regions in which the above-mentioned connectingbridges 28 to 33 were provided apertures 61, 62, 63, 64, 65 produced bya stamping or punching process.

If the apertures 61 to 65 were made without any prior precautions, itwould result in the two connecting plates 12 and 13 in each lead-frame 6to 11, together with the chips 41 to 46 that are connected to the twoconnecting plates 12 and 13, no longer having any mechanical connectionto the frame base 3, which would mean that the two connecting plates ineach lead-frame 6 to 11 and the chips 41 to 46 connected thereto woulddrop out of the frame base 3. To stop this from happening, there areprovided in the lead-frame configuration 60 two reinforcement strips 66and 67 extending in the longitudinal direction 2 of the lead-framestrip. The two reinforcement strips 66 and 67 are connected both to theframe base 3 and to each lead-frame 6 to 11, this being done in eachcase by a layer of adhesive that cannot be seen in FIG. 3. Theconnection of the two reinforcement strips 66 and 67 to the frame base 3and to the lead-frames 6 to 11 can be performed by bonding on thereinforcement strips 66 and 67 by means of the layer of adhesive. Theconnection of the two reinforcement strips 66 and 67 to the frame base 3and to the lead-frames 6 to 11 may preferably be performed by alamination process in which, as is known, a connection is made byapplying pressure and, if required, heat to heat up the adhesive. Itshould be mentioned at this point that the connection of the tworeinforcement strips 66 and 67 to the frame base 3 and to thelead-frames 6 to 11 can be performed before the chips 41 to 46 areconnected to the lead-frames 6 to 11, which has the advantage that thechips 41 to 46 are then not exposed to any mechanical loads caused bythe connection of the reinforcement strips 66 and 67 to the frame base 3and to the lead-frames 6 to 11.

By virtue of the fact that in the lead-frame configuration 60 shown inFIG. 3 there is no longer any electrically conductive connection betweenthe connecting plates 12 and 13 in each lead-frame 6 to 11 and the framebase 3, a testing operation can now be performed. In a testing operationof this kind, a contact electrode belonging to a testing device isbrought into electrically conductive contact with each connecting plate12 and 13, following which a test can be performed on the chips 41 to 46connected to the connecting plates 12 and 13 by means of the testingdevice.

The lead-frame configuration 60 shown in FIG. 3 can be passed on forfurther processing on completion of the requisite testing procedure. Thelead-frame configuration 60 in FIG. 3 may, for example, be passed on bythe manufacturer of the said lead-frame configuration 60 to amanufacturer of chip cards that communicate without physical contact orto a manufacturer of RF tickets, RF tags or RF labels that operate bynon-contacting means. The lead-frame configuration 60 shown in FIG. 3 isadvantageously passed on in a so-called reel form, which is particularlyadvantageous with regard to transportation that is as easy and efficientas possible.

At the company at which the lead-frame configuration 60 is subjected tofurther processing, the connecting plates 12 and 13 plus the chips 41 to46 are separated from the frame base 3 and the reinforcement strips 66and 67 are cut, in each of which cases a unit comprising two connectingplates 12 and 13, a chip 41 to 46 and a reinforcement ribbon isobtained, which unit is referred to in specialist circles as a module. Amodule of this kind is inserted or introduced into the end product to bemanufactured. In the continuing sequence, the connecting plates 12 and13 of each module are then connected, for example, to the two connectingcontacts of a transmission coil forming part of the given end product.Once the connecting plates 12 and 13 have been connected in this way,for example, to the connecting contacts of the transmission coil, thegiven end product is obtained, which in this case is a data carriersuitable for non-contacting communication performed by means of thetransmission coil.

A module 70 as mentioned above is shown in FIG. 4. The module 70 has thetwo connecting plates 12 and 13 and the chip 41. The module 70 is alsoprovided with a reinforcement ribbon 71 that has been obtained from thecut reinforcement strip 66 and that is connected to the connectingplates 12 and 13, being so connected via a layer of adhesive that can beseen neither in FIG. 3 nor FIG. 4.

FIG. 5 shows the module 70, which module 70 is held in a data carrier 72of which only part is shown. The data carrier 72 is a so-called chipcard in the present case. The data carrier 72 may also be what is termeda label or tag however. As can be seen from FIG. 5, the chip 41 has beenconnected to the two connecting plates 12 and 13 by the flip-chiptechnique, in which the chip connections 47 and 48, which are alsoreferred to in specialist circles as bumps, have been connected to thetwo connecting plates 12 and 13 by a thermal compression process.

What can also be seen from FIG. 5 are the reinforcement ribbon 71 andthe layer 73 of adhesive that is provided between the reinforcementribbon 71 and the two connecting plates 12 and 13. In the case of themodule 70 shown in FIG. 4, which was produced using the lead-frameconfiguration 60 shown in FIG. 3, only the reinforcement ribbon 71 andthe layer 73 of adhesive are provided.

In the case of the module 70 or data carrier 72, the arrangement isadvantageously such that the reinforcement ribbon 71 is formed by afiber-reinforced film of plastics material. It is also particularlyadvantageous for the arrangement to be such that the layer 73 ofplastics material is produced from an adhesive that is well suited totransmitting shear forces that may possibly occur in the region betweenthe connecting plates 12 and 13 on the one hand and the reinforcementribbon 71 on the other hand. A fiber-reinforced film 71 of this kind ispreferably produced with the help of glass fibers. The adhesive is anadhesive that is resistant to shear forces and that thus cannot beelastically deformed by such shear forces.

What is advantageously achieved by the provision of the reinforcementribbon 71 made from a fiber-reinforced film of plastics material and bythe provision of the layer 73 of adhesive having the above-mentionedproperty is that tensile or thrust forces that may possibly be exertedon the two connecting plates 12 and 13, which forces produce shearforces between the two connecting plates 12 and 13 and the reinforcementribbon 71, are transmitted by means of the layer 73 of plastics materialdirectly to the reinforcement ribbon 71 with no loss of force and arewithstood by the reinforcement ribbon 71, without this causing anydeformation of the reinforcement ribbon 71 or the layer 73 of adhesive,thus reliably ensuring that no undesirably high forces can be exerted onthe connections between the chip connections or bumps 47 and 48 on theone hand and the connecting plates 12 and 13 on the other hand, whichmeans that these connection are very well protected. This is a greatadvantage particularly when the module 70 is used in a data carrier 72,because a data carrier 72 of this kind may be exposed to relatively highbending stresses.

As can be seen from FIG. 4, in the case of the module 70 the dimensionW1 of the reinforcement ribbon 71 is equal to the width of thereinforcement strip 66 on the lead-frame configuration 60. By selectingthe dimension W1, a state of affairs is produced where all the aperturesthat are provided adjacent to the chip 41 in the connecting plates 12and 13 are covered by the reinforcement ribbon 71. In a variant versionof the module 70, the reinforcement ribbon 71 may also be of a differentdimension, namely a dimension W2, as indicated in FIG. 4. What isachieved in this way is that the apertures that are provided in theconnecting plates 12 and 13 outside the dimension W2 are not covered bythe reinforcement ribbon 71. This has the advantage that the aperturesthat are provided outside the dimension W2, which are provided for thepurposes of strain relief, are not restricted in respect of the actionthey perform for the purposes of strain relief.

What is also shown in FIG. 5 at the same time as the module 70 describedabove is an advantageous further embodiment of a module 70 of this kind.In this further embodiment of the module 70, there are provided on thefiber-reinforced film of plastics material that is intended to act as areinforcement ribbon 71 three further layers 74, 75 and 76. The firstfurther layer 74 is a protective layer 74 that is composed of metal. Thesecond further layer 75 is a damping layer 75 that is composed of adamping material, a paper-like material being selected as a dampingmaterial in the present case. A rubber-like material may however also beused. The third further layer 76 is a fastening layer 76 that iscomposed of a fastening material, an adhesive material being selected asthe fastening material in the present case.

The protective layer 74 composed of metal is produced by a vapordeposition process and has a thickness of approximately 100 nm. Theprotective layer 74 acts as a barrier against moisture and also acts asa light-screen against ultraviolet radiation and infrared radiation andacts in addition as protection against radio-frequency waves.

The damping layer 75 has the advantage that, during the furtherprocessing to which the advantageous further embodiment of the module 70is subjected to allow a data carrier 72 to be manufactured, it damps thepressure on the chip 41 that occurs in the course of this, for example,in a lamination process and thus appreciably reduces the risk of a chipfracture.

The fastening layer 76 can be used to enable the advantageous refinementof the module 70 to be provisionally held fast on a carrier film that isprovided with a transmission coil, after which an electricallyconductive connection is made between the connecting plates 12 and 13and two coil connecting contacts of the transmission coil, for example,by a crimping operation or by means of an electrically conductiveadhesive or by a soldering process or a welding process, after which thecarrier film provided with the transmission coil plus the module whichis provisionally held firm on it by means of the fastening layer 76 isconnected to other films in a laminating process and the complete datacarrier 72 is produced in this way. The fastening layer 76 may becomposed of an electrically insulating material, which has the advantagethat, to allow the module 70 or rather its two connecting plates 12 and13 to be connected to two coil connecting contacts of a transmissioncoil, the module 70 can be positioned transversely over the turns of thetransmission coil without this causing a short-circuit between the turnsof the coil.

It should be mentioned at this point that in other advantageous furtherembodiments of the module 70, it is also possible for only one or onlytwo of the three layers 74, 75 and 76 described above to be provided onthe reinforcement ribbon 71. Layers of other forms may also be providedfor other intended uses.

1. A lead-frame configuration that is strip-like in form, that has aframe base and that has a plurality of lead-frames that are connected tothe frame base and that are situated next to one another in thelongitudinal direction of the strip, each of which lead-frames isintended to receive a chip wherein, each lead-frame has at least twoconnecting plates wherein there being is provided for the lead-framesthat are situated next to one another in the longitudinal direction ofthe lead-frame strip a reinforcement strip that extends in thelongitudinal direction of the strip and is connected both to the framebase and to the connecting plates of each of the lead-frames that aresituated next to one another in the longitudinal direction of thelead-frame strip, the connection being made by means of a layer ofadhesive, wherein the reinforcement strip is formed by afiber-reinforced film of plastics material and wherein the layer ofadhesive is produced by means of an adhesive that is suitable fortransmitting shear forces that may possibly occur in the region betweenthe connecting plates on the one hand and the reinforcement strip on theother hand.
 2. A lead-frame configuration as claimed in claim 1, whereinat least one further layer is provided on the reinforcement strip formedby a fiber-reinforced film of plastics material.
 3. A lead-frameconfiguration as claimed in claim 2, wherein at least one further layeris provided on the reinforcement strip formed by a fiber-reinforced filmof plastics material, which at least one further layer belongs to thegroup of layers detailed below, which group comprises: a protectivelayer that is composed of metal, a damping layer that is composed of adamping material and preferably of a paper-like material, and afastening layer that is composed of a fastening material and preferablyof an adhesive material.
 4. A module that is produced with the help of alead-frame configuration and that has at least two connecting plateseach of which is connected to a connecting contact of a chip, and thathas a reinforcement ribbon that is connected to the connecting plates,the connection being made by means of a layer of adhesive, wherein thereinforcement ribbon is formed by a fiber-reinforced film of plasticsmaterial and wherein the layer of adhesive is produced by means of anadhesive that is suitable for transmitting shear forces that maypossibly occur in the region between the connecting plates on the onehand and the reinforcement ribbon on the other hand.
 5. A module asclaimed in claim 4, wherein at least one further layer is provided onthe reinforcement ribbon formed by a fiber-reinforced film of plasticsmaterial.
 6. A module as claimed in claim 5, wherein at least onefurther layer is provided on the reinforcement ribbon formed by afiber-reinforced film of plastics material, which at least one furtherlayer belongs to the group of layers detailed below, which groupcomprises: a protective layer that is composed of metal, a damping layerthat is composed of a damping material and preferably of a paper-likematerial, and a fastening layer that is composed of a fastening materialand preferably of an adhesive material.
 7. A data carrier, wherein thedata carrier contains a module as claimed in claim 4.